When a device wakes up, what about the cpu , is it still on idle with cpuidle ? for example how a mouse move trigger the screen to wake up ?
This is a case of system suspend/resume. Your mouse is a wake-up device. It is configured to send wakeup interrupts. It would wake up the cpu first and then the cpu wakes up all the devices.
On Mon, Sep 8, 2014 at 9:16 PM, AYAN KUMAR HALDER <ayankumarh@gmail.com> wrote:
When a device wakes up, what about the cpu , is it still on idle with cpuidle ? for example how a mouse move trigger the screen to wake up ?
This is a case of system suspend/resume. Your mouse is a wake-up device. It is configured to send wakeup interrupts. It would wake up the cpu first and then the cpu wakes up all the devices.
Hi, Do you mean runtime suspend/resume ? Why will the mouse wake the cpu from idle (cpuidle) ? Isn't it that the wakeup source will wake only the specific device which was runtime suspended ? Thanks
> Hi, > Do you mean runtime suspend/resume ? No, I am talking about system suspend/resume (suspend to RAM, etc). > Why will the mouse wake the cpu Because it has been configured as a wakeup device. > from idle (cpuidle) ? Isn't it that the wakeup source will wake only > the specific device which was runtime suspended ? Thanks You are bringing too many things here. 1. cpuidle is a different concept. 2. The situation you had described above is not of runtime-suspend. "Movement of mouse wakes up the system"
On Mon, Sep 8, 2014 at 9:57 PM, AYAN KUMAR HALDER <ayankumarh@gmail.com> wrote: >> Hi, >> Do you mean runtime suspend/resume ? > No, I am talking about system suspend/resume (suspend to RAM, etc). > >> Why will the mouse wake the cpu > Because it has been configured as a wakeup device. > >> from idle (cpuidle) ? Isn't it that the wakeup source will wake only >> the specific device which was runtime suspended ? Thanks > You are bringing too many things here. > 1. cpuidle is a different concept. > 2. The situation you had described above is not of runtime-suspend. > "Movement of mouse wakes up the system" Hi Ayan, Yes, I know...This is exactly the point in PM I don't understand yet... I try to configure the linux in my board to do it all automatically (this are actually my requirements) , i.e. using the following mechanism: cpuidle, cpufreq, DVFS & runtime PM. Now, the thing I don't yet understand is what the wakeup source means in this configuration. Wakeup only for a specific device driver ? Thanks for clarification this issue for me.... Ran
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Ran Shalit